Activity in the optics industry has been directed towards the development of a Wavelength-Division-Multiplexed (WDM) Automatically Switched Optical Network (ASON), which allows client network devices such as IP routers and ATM switches to automatically request bandwidth from the network when the need arises. Light-path (i.e., wavelength) connections in an ASON environment may be required to traverse a number of fiber links. These links may include optical amplifiers (OAs) and optical cross-connects (OXCs) which add noise and distort signal-bearing light pulses. Thus, the network is faced with the problem of delivering an acceptable level of performance for the connection.
One approach to address the quality of service for a connection is to architect a network topology such that every reasonable physically realizable light path delivers an adequate level of performance with little or no impact on every other light-path. Such a paradigm is known as “Islands-of-Transparency”, since the ASON is divided into a set of smaller sub-networks or “islands”. Within these sub-networks, paths are capable of delivering some universally acceptable quality of service. The sub-networks are required to be interconnected via optical-electronic-optical cross-connects (OEO-OXCs) which are capable of regenerating the signals in the electronic domain, thereby reducing undesirable optical transmission impairments. Network clients that reside in different sub-networks are required to establish paths through the OEO-OXCs regardless of their physical proximity. The large number of OEO-OXC devices that are required to support the “Island of Transparency” network topology make the topology costly to implement.
Thus, what is required is a method and apparatus for determining selecting and validating a path/connection through a switched optical network that is capable of delivering an acceptable level of performance that is both efficient and economical.